Decline of hepatitis C virus load in serum during the first 24 h after administration of interferon-beta as a predictor of the efficacy of therapy

Background/Aims: Hepatitis C virus (HCV) kinetics during interferon (IFN)-alpha treatment have been evaluated recently, however, little is known about the resultant viral kinetics in IFN-beta treatment. In this study, we evaluated HCV kinetics during the first 24 h of IFN-beta treatment, and also assessed their relationship to therapeutic outcomes. Methods: We measured HCV RNA levels at 0 and 24 h after the initiation of IFN-beta treatment, and we calculated the decay slope, viral half-life, and viral production and clearance. Then we analyzed these factors as they related to therapeutic responses with IFN-beta as well as to clinical variables, i.e. genotype, diversity of hyper variable region, and histological findings. Results: Patients with sustained responses (SR) displayed steeper decay slopes of the viral load than those without SR (2.87±1.41 vs. 1.82±1.66, P=0.031). On the other hand, the decay slope was not affected by the clinical variables. The values of viral half-life and viral production and clearance showed no significant correlation to the response and the clinical variables. Conclusion: This study demonstrated that the decay slope of the viral load during the first 24 h is related to the virological response to IFN-beta treatment.